Regulus sinks on clinical hold

Regulus Therapeutics Inc. (NASDAQ:RGLS) said FDA placed a full clinical hold on RG-101 after the company reported a second case of jaundice, a severe adverse event (SAE), in an ongoing Phase I study to treat chronic HCV. Regulus fell $2.76 (55%) to $2.25 in early after-hours trading on Monday after reporting the news.

In the new case, the patient experienced a jaundice event 117 days after receiving a single dose of RG-101. Regulus acknowledged the first case in April, when it reported updated interim data from a Phase II trial of the HCV therapy. The first patient developed jaundice 21 days after completion of therapy, which included a single dose of RG-101 followed by 28 days of treatment with Daklinza daclatasvir and a second dose of RG-101 on day 29 (see BioCentury Extra, April 15). ...